Preparation And Characterization Of Optically Induced Dielectrophoresis Chip Based On Magnetron Sputtering

With the development of MEMS technology,the third generation nanopore DNA sequencing has made more and more progress.However,the problems such as the excessive speed of DNA and the complex signal are still hindering its further study.The development of micro-nano particle manipulation technology based on light-induced dielectrophoresis(ODEP),it is a significant research direction to realize the real-time manipulation of DNA and to control the rate of it through the nano-hole by the light-induced dielectrophoresis force.The key part of the ligh-induced dielectrophoresis chip is the thin film of hydrogenated amorphous silicon.The electrical properties and microstructure of a-Si:H thin filmsdetermined the effect of light-induced dielectrophoresis on the manipulation of nanoparticles.Therefore,preparing good electrical properties and surface structure of amorphous silicon thin film is very necessary.The conventional a-Si:H films were prepared by plasma chemical vapor deposition(PECVD),which has the defect of the low deposition rate,dangerous reaction gas.So,with the use of simple magnetron sputtering process,low deposition temperature,good film adhesion,we studied the electrical properties and micro structure of a-Si:H thin films prepared by magnetron sputtering.In order to find out the best performance of a-Si:H films,and for the light induced dielectrophoresis chip.This paper mainly studies the following aspects:(1)The effects of sputtering power,deposition pressure and deposition temperature on Microstructure and deposition rate of a-Si:H thin films.The properties of the films were characterized by Raman spectroscopy and AFM microscopy.The results showed that the sputtering rate of the films increased with the increase of the power,the decreasing pressure and the increasing temperature,and showed the characteristics of the parabola.The surface roughness of the films increases with the sputtering power,the pressure increased,and decreasing temperature.Comprehensive experimental results,we conclude that when the sputtering power is 150W,the sputtering hydrogen partial pressure is 3Pa;the sputtering temperature is 250 ?the deposited film has the best surface morphology and the fastest deposition rate.(2)Effects of different boron doping concentration on the properties of the films.With the increase of boron doping concentration,film defects increase,and the films's conductivity also increase.We summarize when the boron doping amount is 0.03%,the film has the best electrical properties and best surface structure.(3)Illumination,oxidation and temperature have a great influence on the properties of a-Si:H thin films due to their instability.(4)The preparation process and method of a solid nanopore are studied.Then,the transport of ions at different concentrations was studied by experimental measurements and numerical calculations(5)Finite element simulation of light induced dielectrophoresis chip using ANSYS finite element software.